With his wacky sense of humor and flair for publicity, Mechai Viravaidya is regarded as something of a miracle worker for helping to rein in Thailand's booming population growth in a single generation. Now he's hoping to work a second miracle as he directs a nationwide campaign against AIDS. "AIDS is a problem which will inevitably enlarge in Thailand because of drug use and prostitution," Mechai said in a recent interview. "But three years ago, nobody was doing anything about it.

With his wacky sense of humor and flair for publicity, Mechai Viravaidya is regarded as something of a miracle worker for helping to rein in Thailand's booming population growth in a single generation. Now he's hoping to work a second miracle as he directs a nationwide campaign against AIDS. "AIDS is a problem which will inevitably enlarge in Thailand because of drug use and prostitution," Mechai said in a recent interview. "But three years ago, nobody was doing anything about it.

There's good news for Thailand on two fronts: Emergency aid from the International Monetary Fund will end on schedule in June, confirming that economic recovery is truly underway. And the nation's population growth has dipped below 1% a year. The linkage between the unrelated news items is more than casual. For a generation, Thai governments have believed that economic well-being is impossible without restrained population growth.

Airing on PBS over the next three nights, "Rx for Survival: A Global Health Challenge," is the somewhat dry title of a compelling, six-hour overview of health crises around the world, with detours into medical science and history. As a TV experience, it's a medical thriller, in a sense, about outbreaks.

The Thais make salads with raw garlic, cashew nuts, fried eggs, sardines . . . almost any ingredient they can think of. But a salad made with condoms? It's the signature dish of a Bangkok restaurant called Cabbages & Condoms, which partly exists to raise funds for AIDS prevention and family planning. But not to worry.

The inflation of Malcolm Potts' six-story condom on a vacant lot next to the Montreal convention center this week may go down in the history of the AIDS epidemic as a small but telling symbol of the strange marriage of science and guerrilla theater. For one bright, shining moment, the banana-colored prophylactic bobbed gracefully against the crepuscular Quebec sky. Television cameramen spilled forth from the Fifth International Conference on AIDS to seize the first Nielsen-pleasing visual of a long, long day. "I'm going to take a picture of my own condom!"

Poverty is a birthmark for the people of Thailand's northeastern provinces, where a bicycle suggests middle-class status and jobs outside the sugar cane fields are few. For most, Bangkok is the honey pot and migrating there is a rite of passage into adulthood. One of every six Thais works in the metropolitan Bangkok area, which is said to produce half the country's gross domestic product. Wages in the capital are 12 times higher than here in Chakkarat.

As an up-and-coming young Thai professional during the mid-1980s, K. Surapong regularly ended long workdays with a few drinks with his buddies and sex with prostitutes--sometimes protected, often not. Surapong, now with full-blown AIDS, has spent the last few years as one of the country's leading "guinea pigs," testing an array of drugs that temporarily arrest the symptoms of the virus.

The classic image of Asia is rural: A peasant in straw hat stooped over in a verdant green checkerboard of rice paddies. But the bucolic vision of Asia is being rapidly transformed. By the year 2020, according to projections by the United Nations, most of Asia's population will live in cities. The new image of Asia is a slum dweller, living without such necessities as sanitation and fresh water and commuting to a factory job through increasingly gridlocked traffic.

Under the bridge in Klong Toey's massive slum and around Bangkok's railway station, Thai boys gather nightly. Preteen labor is illegal in Thailand, but these kids work in shoe factories, gas stations or fisheries, even heavy labor. Others are child prostitutes or live off petty crime. Many are homeless. The boys roughhouse, play with popguns and wait for "tricks," victims or employers who look for cheap labor at the rail station. Sniffing glue and paint thinner is now chronic in this age group.